Implanted device turns thoughts into motion


Using an implanted brain-computer interface, researchers at the Miami Project to Cure Paralysis were able to help German quadriplegic Aldana Zuniga regain some independence by allowing her to use her hand just by thinking about it.

When German Aldana Zuniga was 16, doctors told him he would never be able to walk or use his arms properly again.

But Zuniga never gave up on the idea.

Now, nine years after a car accident left him paralyzed, Zuniga is making significant progress. Using a surgically implanted brain-computer interface (BCI) that can decipher his thoughts, Zuniga recently drove an adapted NASCAR race car around Pikes Peak International Raceway in Colorado, just thinking about grabbing the throttle. .

He also connects his BCI to an adaptive glove every day to help him regain control of his right hand to open doors, feed himself, write short notes and brush his teeth.

In 2018, as part of a research study, Zuniga volunteered to surgically implant the BCI to see if the technology could improve the lives of people like him who live with spinal cord injuries. It was the first time doctors from the Miami Project to Cure Paralysis, a center of excellence at the University of Miami’s Miller School of Medicine, implanted a BCI solely for research purposes, said David McMillan, director education and awareness for The Miami. Project, as well as an assistant professor of neurological surgery.

“Finding someone brave enough to get a brain implant when they didn’t need it was tricky,” said McMillan, who facilitates numerous Miami Project clinical trials for people with spinal cord injuries. spinal. “There was no guaranteed upside, but German’s courage and spirit of exploration was incredible.”

Two weeks after her surgery, Zuniga met with the research team, which includes study leader Abhishek Prasad, associate professor of biomedical engineering; Dr. Jonathan Jagid, professor of clinical neurosurgery; Dr. Michael Ivan, associate professor of neurosurgery; Dr. Iahn Cajigas, former neurosurgery resident; and Kevin Davis, a graduate student in Prasad’s Neural Interfaces Lab at the Miami Project.

By tricking Zuniga into thinking about the natural task of opening and closing her hand, the researchers were able to create software that could read her unique brain signals and send them to the glove. Soon, as long as he was wearing the glove, Zuniga could move his thumb, index and middle fingers with his right hand.

“It meant a lot to see my fingers moving again,” said Zuniga, now 25. could help people all over the world who suffer from spinal cord injuries.

Zuniga’s progress is the result of her own determination, as well as the hard work of Miami Project researchers, who share the goal of helping people with spinal cord injuries regain movement. Jagid, who implanted Zuniga’s BCI, said his team searched for more than six years for a candidate for this experimental surgery and was lucky to find Zuniga.

“German is a very driven and selfless person who wants to help everyone he can overcome a spinal cord injury,” Jagid said. “I wasn’t surprised that he was able to drive this car because if you know German he’ll get there.”

Now the team has other goals for the BCI: to help Zuniga use both hands, and maybe also his legs. Zuniga may also have the chance to drive an adapted boat one day.

It’s been a long journey though.

After the car accident left him paralyzed, Zuniga spent six months in the hospital and a year of his life in rehabilitation while working to complete his first year of high school. But like other spinal cord injury survivors, Zuniga tries to stay active to avoid further muscle spasms or atrophy. He was training in the Miami Project gym and participating in other clinical trials when he read a newsletter about a study looking for people with spinal cord injuries to volunteer to be implant a BCI. As this could help him regain some independence, Zuniga was intrigued.

Zuniga was vetted for the study, which included meeting strict qualification criteria. And once he turned 21, he had surgery. Jagid said his team chose this specific BCI because it was less invasive than others and was designed to detect brain signals. The actual device is just a tiny strip of sensors that sits on the brain, with a generator placed just below the shoulder bone and a small wire that connects the two. Another advantage is that the BCI is completely concealed in the body. Therefore, if Zuniga decides he wants the BCI removed later, the surgery is reversible, Jagid said.

Led by Ivan and Jagid, the surgical team determined where to place the BCI on Zuniga so that it would have the most impact. It now relies on a small area of ​​the brain that controls hand movement, called the hand motor button.

“Our thought was that if we could just allow him to start the hand motion again while thinking about it, that might help him tremendously, and that’s how it happened,” Jagid added.

With the BCI in place, Davis, Prasad and others devised software to decode Zuniga’s brain signals from the device. They asked her to think about the opening and closing of her hand, then trained the BCI to pick up these unique signals from the part of the brain responsible for the movement of her right hand. Over time, their work allowed Zuniga to not only control the glove, but Zuniga was also able to use his BCI to control a robotic walking device on a treadmill at the Miami Project in 2019.

“It was good to be back on my feet and see my legs moving when I thought about it,” Zuniga said. “It was amazing.”

Davis, a self-taught software engineer who studied neuroscience in college, then figured out how to make the decoder portable so Zuniga could use the BCI outside the lab. Davis even developed a cellphone app that connects to the BCI via Bluetooth and prompts Zuniga to think about opening and closing her hand. Then, a minicomputer in Zuniga’s backpack connects his brain signals to control a device, usually the Adaptive Glove.

“The BCI extracts data from the brain and then it sends information to another device like the glove, or in the most recent case, a car accelerator,” said Davis, an MD/Ph.D. Medical Scientist Training Program, currently doing her graduate studies in Biomedical Engineering.

Just before the onset of the COVID-19 pandemic, Davis finished tweaking the BCI portable set-top box. This was particularly fortuitous as Zuniga was able to practice his new skills at home for the past two years, and Davis was able to hone the software remotely when needed. He is also able to collect data on Zuniga from home and is gathering evidence of the usefulness of the BCI setup for people with spinal cord injuries.

Jagid said Zuniga is the only person with a spinal cord injury he knows with this mobile configuration, while other BCI patients usually have a visible device protruding from their head and need to be in a lab to connect it to a machine that decodes their brain signals.

“The great thing about this device and the current setup is that it can be used at home, so he can really benefit from the renewed use of his hand,” added Jagid. “The German has become very good at being able to do this seamlessly.”

There are myriad benefits to the flexibility of Zuniga’s transportable BCI, McMillan added.

“Currently other people may have BCIs that have a wider signal and could send more advanced commands [from their brain], but because this one is simpler and allows German to be used in a variety of contexts, it’s able to explore more and further than the others,” McMillan said. “He uses it to perform simple daily living activities and to control really advanced robotics, like an 850 horsepower NASCAR race car.”

To drive the car this spring, an opportunity made possible by Falci Adaptive Motorsports, some tweaks were made to the BCI software to work with the car’s technology, but not much, Davis said. Zuniga still needed to think about opening and closing his hand to engage the throttle, used an adaptive helmet to steer, and had a special device attached to the helmet where he inhaled or “sipped” to brake.

“We practiced several times before leaving, but German was still using the same motor imagery of opening and closing the hand, which he is quite familiar with,” Davis said. “He just needed to understand the sensitivity of it to apply to gas.”

While there was a safety driver in the car with him, Zuniga was exhilarated by the experience of driving a race car.

“After the first round I lost my fear and the feeling of freedom was amazing,” he said. “To see how I was able to control a car is something I never thought this device could make possible.”

The next step for the team is to expand the applications of Zuniga’s currently implanted BCI by trying to extract more unique signals from his brain. This could allow for a more complex function, such as using both hands. At the same time, the team is studying other brain-computer interfaces that could allow future patients to have more freedom and restore function.

Zuniga had always hoped to go to college after graduating from high school in 2015. After seeing the power of technology through his own experience, he decided to become a computer science student at Miami-Dade College and hopes now being able to program brain devices to help others like him gain mobility.

“Working with BCI sparked an interest in me because I saw what you could do with the technology,” Zuniga said. “It made me want to help improve it and even create a new device one day.”

Additional Miami Project BCI study team members include: Annie Palermo, Noeline Prins, Jasim Ahmad, Steven Vanni, Sebastian Gallo, Audrey Wilson and Letitia Fisher.


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